Usually, laser disks are glued onto disk-shaped heat sinks (disk carriers) that are cooled on the rear side by impingement flow. The thermomechanical properties of the disk carrier substantially determine the thermal lens effect of the laser disk. This leads to demanding requirements for the thermal conductivity and stiffness of the disk carrier, which is therefore made of chemical vapor deposition (CVD) diamond. For higher laser power outputs, this leads to thicker diamond disks and high production costs. In other words, greater stiffness with almost the same heat resistance is achieved by ever thicker diamond disks.
An impingement cooling device disclosed in US 2014/0190665 A1 has a single cutout adjoining the rear side of the carrier plate, and radially running return lines.
In the impingement cooling device disclosed in WO 2011/130897 A1, a laser disk is mounted on a carrier plate, which at the same time forms a resonator mirror of a laser resonator. A cooling liquid emerging from a nozzle opening impinges on the self-supporting rear side of the carrier plate, which is thereby cooled.
EP 1 213 801 A2 discloses a cooling device in which the laser-active solid body is cooled directly with cooling water on its rear side, which is provided with a covering layer.
U.S. Pat. No. 6,339,605 B1 discloses a cooling arrangement for a laser disk mounted on a copper substrate. A cooling liquid flows through the copper substrate and is conducted into micro-channels of the copper substrate that are open toward the laser disk. The rear side of the laser disk is consequently cooled by the cooling liquid flowing through the micro-channels.
Furthermore, US 2007/0297469 A1 discloses a cooling arrangement for a laser disk mounted on a carrier plate of diamond or sapphire. Within the carrier plate, micro-channels for a cooling liquid run near the surface.